Annealing cover



March 16, 1937. E. N. mm 2,074,093

ANNEALiNG COVER Filed Aug. 26, 1935 2 Sheets- Sheet 1 641 v Eta-.3. F1L2.4L

[3' INVENTOR.

EDWA RD N MLLAM I ATTORNEYS.

March 16, 1937. E. N. MILLAN ANNEALING COVER Filed Aug. 26, 1935 2 Sheets-Sheet 2 v INVENTOR.

EOWARD NN/LLA N.

BY "m fizwr 60% ATTORNEYQS.

Patented M. 16, 1937 uN 'r o STATES PATENT OFFICE to The American Bolling .Mill Company, Middletown, Ohio, a corporation of Ohio Application August 28,

1935, Serial N0. 37,858

'1 Claims. (01. 263-49) My invention relates to annealing covers for covering pacl'rs oi'sheet metal or coils while they arelbeing heat treated, and is acontinuation ,in partoi my copending application Serial No. 8,083, flied January 23, 1935. The uses of" annealing covers are well known, and particular description thereof is not necessary. The em,

' ployment of annealing covers to retain particular atmospheres surrounding the pieces being" heat treated is'also well known. Because of their uses, annealing covers should be relatively rigid, but at the same time they should be as light as possible, both ior convenience in handling and also for emcient heat transfer. This desirable lightness has not been attained in the cast annealing covers in-current use. Ithas hitherto forthe most part been considered necessary to provide a great bulk of metal to give satisfactory rigidity under high heats. Because of the rough usage and the great heat to which annealing coversare subjected, they must of course be very rugged and strong. Another ,difliculty present where gaseous media under pressure are introduced into the box while'hot, is that there is a tendencyfor the sides to bulge. The rough handling to which such covers are subjected also. has a tendency to cause the rooi to sag.

It is an object of my invention to provide an annealing cover which is extremely strong-and rigid and capable of forming a gas tight chamber,

and very resistant to heat and wear, but which is at the same time-light in weight.

It is a further object of my invention to pro-' vide annealing covers which fire relatively inexpensive to construct but which when ccn- I structed have all of the above advantages.

I Another obiect'oi my invention is to provide annealing covers having the above mentioned desirable qualities which may be constructed with a minimum of welding.

Still another object 0! my invention is to-pro-' vide annealing covers 01' such a construction that the tendency of the covers to bulge outwardly under the influenceoi' hot gases is neutralized. These and other objects oi my invention which will be set forth hereinafter, or will be apparent to one skilled in the art upon reading these specifications, I accomplish by that certain cono 'struction and arrangement-0t parts of which I shall now describe a preferred embodiment.

Rates-once is made to the drawings which form apart hereof, and in which:

i'igure 1 is an end elevation with part cut away, cl my annealing cover. V

Figure 2.1a a side elevation or the same with I part cut away. a

Figure 3 isv view corresponding to Figure 1 of amodiiled construction. Figure 4 is a side elevation of the modified consgructionjof Figure 3," corresponding to Figure 0 Figure 5 is a section taken on the line 5 of Figure 2.

Figure 6 is an and elevation with part cut away 01 amodiflcation oi my cover.- Figure 7 is a side elevation of the same with part cut away.

Broadly my invention comprises providing an annealing cover formed of relatively heavy corrugatedmctalsheets welded together to form the .desired sealed chamber. .The corrugated sheets which Ipreierto use-are oi rough plate, by which I mean' the product of the modern continuous mill, which isof a weight of 8 to 12 gauge or thereabouts, and are weldedtogether with strengthening struts or hands where desired, "to form a chamber, with sides, ends and a top, to ilt over a pack or stack of sheets while they are being annealed.

I prefer to use an alloy containing 15% or more of chromium, and 85% or less of iron.

I may further use 'an'ralloy containing 25% .chromium, l2% nickel, and 63% iron. However, variations in the percentage oi metals used in the alloys may made without departing from the scope of my invention.

Briefly, in the practice or my invention, 1 provide a chamber or annealing coverhaving four sides i, I, and l formed of a relatively heavy corrugated sheet metal." These side pieces I, 2, i and 4 are'so positioned as to form a hollow rectangle with the corrugations 8 vertical and. with the ends 0! the sheets abutting. These ends are preferably welded to each other so as to iorm an integral unit of the -sides I, 2, 3, and

4, all as described -in myf'copending application sheets, say with corrugations having a depth of substantially 1% inches and a pitch of six inches, and where the corrugated pieces'are to be curved, this is done progressively between dies. The figures given are, of course, exemplary and not limi About the lower edges of the four sides I, 2, 3 and 4, I place four strips of iron 8, and weld them to the lower edges of the said sides along their contacting portions. The ends of the four 5 irons 8 may be beveled and welded to each other in order to form an integral frame. The welding may be done in any convenient com'rnercialway, as by electricity or flame. The top portion I2 is in the shape ofan arch andis fastened to the side walls i and 3 by means of strips I 3 of metal welded to the ends of the corrugations 5. These strips l3 are wider than the end of the corrugations of the side .walls and a portion ll of them is permitted to 5 project over the side walls I and 3 and into the chamber. This portion i4 is bent over so as to contact the ends of the corrugations of the bent portion of the top- I2, and at a right angle to the same. In other words if the top I! is a portion of the segment of a circle, the bent portions i4 would define a radial line of the same circle. Bending the portions l4 in this manner, greatly facilitates construction since it is possible to form the top H of a sheet of corrugated metal with vertical or square cut ends, and then to bend this top l2 into the predetermined arc. This in turn will bring the ends of the corrugations 5a of the top l2 into registry with the surface of the bentover portion M, to facilitate welding. The two ends or side walls 2 and 4 areso configured at their top edges that they will contact the underside of the top i2 when it is in position. Hooks l8 may be welded to the ends or sides of the cover' so as to fit the curved upper ends of the end walls. Along the sides I flatten out lips I30. and turn them outward until they are in a horizontal plane. The roof section is then simply set on top of the side and end walls and welded thereto, thelip I30 taking the place of the member l3 of Figures 1, 29nd 5.

In order to prevent sagging of the roof I may provide the plates 6. These plates are cut out 5 along one edge to conform to the curvature of the arch, and along the other edge there is formed an angle leg id at right angles to the plane of the supporting plate. The plate 6 is welded in several places along the line of contact 55 between the plate and the arch, and the angle leg 8a.. gives it strength in a transverse direction. .As pointed out above, a tendency has been noted forthe side walls of the annealing cover to bulge outwardly due to the gaseous pressure on the inside. To neutralize this tendency I may make the annealing cover of pylon form, having a larger area at the base than at the top, by inclining the side and end walls inwardly, as shown at la, 2a, 3a and 4a in Figures 6 and 65 7. There is a normal tendency in this construction for the walls to sag inwardly, and by proper design, the sagging tendency may be made to neutralize the aforementioned bulging tendency.

The amount of inclination given to the side and end walls will depend on (a) the temperature at which the box is to be used, and (b) the pressure of the introduced medium. The amount that the base dimensions exceed the top dimensions may thus vary from zero to 20%, depending upon factors (a) and (b).

The different configurations and shapes of the cover shown in my drawings are not intended as alimitation, since numerous other forms maybe used without departing from the spirit of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, ls:-

1. An annealing cover comprising vertically corrugated side wall members of plate metal, an are shaped top of laterally corrugated plate metal and a joining strip therebetween, said strip longitudinally bent to form an obtuse angle one leg of which overlies and is welded to the top of the side wall, and the other leg of which is placed flatwise against the end of the top and welded thereto.

2. An annealing cover comprising corrugated side wall members of plate metal, an arc shaped top of corrugated plate metal and a joining strip therebetween, said strip longitudinally bent to form an obtuse angle one leg of which overlies and is welded to the top of the side wall, and the other leg of which is placed flatwise agains the end of the top and welded thereto.

3. An annealing cover comprising corrugated side wall members of plate metal, an are shaped top of corrugated plate metal and a joining strip therebetween, said strip longitudinally bent to form an obtuse angle one leg of which overlies and is welded to the top of the side wall, and the other leg of which is disposed at an angle radial to the curvature of the top and welded to the end thereof.

4. An annealing cover according to claim 2, the side and end walls of which are of such proportions that the horizontal cross sectional area of said cover at its top is smaller, and similar to its horizontal cross sectional area at its base.

5. An annealing cover comprising corrugated trapezoidal side wall members of plate metal, an are shaped top of corrugated plate metal and a joining strip therebetween, said strip! longitudinally bent to form an obtuse angle one leg of which overlies and is welded to the top of the side wall, and the other leg of which is placed flatwise against the end of the top and welded thereto.

6. An annealing cover according to claim 2, the side walls of which are of such proportion that the horizontal cross sectional area of said cover at its top is smaller than its horizontal cross sectional area at its base.

.7. An annealing cover according to claim 2, v

the end walls of which are of such proportion that the horizontal cross sectional areapf said cover at its top is smaller than its horizontal cross sectional area at its base.

EDWARD N. MILLAN. 

